A potential cause of death among race car drivers is injuries that result from violent head movements during a crash. In a typical crash, the driver's body is secured to the vehicle seat with seat belts. However, during a rapid deceleration, a driver's head can continue to move forward, causing a basilar skull fracture resulting in serious injury or immediate death.
A head restraint device is desirable to prevent neck injuries for drivers in race cars. The head restraint device prevents the head of a driver from whipping forward in a crash. The head restraint device additionally prevents excessive rotational movement of the head. Ideally, the head restraint device provides these protections without otherwise restricting movement of the neck.
During use of known head restraint devices, e.g., the “HANS device”, a vehicle driver is able to move his or her head as normal while operating the vehicle. However, in a crash, the device restricts head movements that would otherwise exceed the normal articulation range of the skeletal/muscular system and cause severe injury. Without the HANS device, in a crash, a driver's body is decelerated by the seatbelt while the head maintains velocity until it is decelerated by the neck. The HANS device maintains the relative position of the head to the body and transfers energy to the drivers chest, torso, shoulder, seatbelts, and seat as the head is decelerated.
A typical HANS device is shaped like a U, wherein the back of the U locates behind the neck of the driver. The two legs of the U lie flat along the front of the chest over the pectoral muscles. The device is supported primarily by the shoulders. A typical HANS device is only attached to the driver's helmet, but is not attached the belts, the driver's body, or to the seat. The helmet is attached to the HANS device at two connection locations on each side of the helmet.
When wearing a typical racing harness, the harness belts that cross the driver's upper body pass over the HANS device on the driver's shoulders and the belts buckle at the center of the driver's abdomen. Therefore, the HANS device is secured with the body of the driver, not the seat.
Despite the substantial improvement in driver safety afforded by the use of the HANS device, drivers involved in high speed accidents may experience a concussion when using the device. The majority of concussions in auto racing do not result from the head coming in contact with objects within the vehicle. Instead, concussions experienced by auto racing drivers while using the HANS device may be caused by the straps that are affixed to a driver's helmet. During a crash impact, when the driver's head moves forward and fully extends the straps, the helmet and the driver's skull within the helmet come to an abrupt stop, while the driver's brain continues to move forward until the brain impacts the front of the skull. Therefore, without anything touching the helmet or even getting a scratch, the driver can get a very serious concussion.